the distillation of a mixture of light and heavy oils, and is also 
due to the superiority of the results given by Mr. Warren’s pro- 
cess over those obtained by ordinary fractional distillation. 
Prof, Silliman notices the fact that when 485 ce. were distilled 
0 370° C 
20° t 
per cent of the same grade, or 50 per cent plus 5 ae eee pA 
istillate, a 
pose of correcting, what I am confident is an error, and to as- 
sist in the dissemination of reliable information respecting Cali- _ 
fornia Petroleums, es, 
Providence, R. I., March 6th, 1867, 
Arr, XXXIX.—Contributions from the Sheffield Laboratory of 
Yale College—XIV. On Kaolinite and Pholerite; by S. W. 
JOHNSON and JoHN M. BLAKE. 
THE study of certain minerals termed pholerite, nacrite, stein- 
mark, and kaolin, leads to the conclusion that a num sub- 
Stances whi i arious d 
ite, : 
nly 
